Operating mechanism for timepieces



ug.'19, 1930: N. D. HOLBROOAK 1,773,308

OPERATING NIECHANISM-FOR` TIMEPIECES Filed Feb. 7, 1928 Patented Aug. 19, 1930 narrar staf-rss wages NEWTON D. HoLBRooK, oFl'rHoMAsToN', coNNEotroUT OPERATING LIECHANISM FOR TIZMEPIECES Application filed February 7, 1G23.- i Serla11\o.-252,487.

This invention relates to mehcanism which is designed for driving the time trainot watch and clock movements in which the sourcexof power is electrical, and whileit is is; serviceable for electric .clocks generallyt is,l

isiillustratedand described in myPatent No., 15. 1,662,920,`granted March 20,' 1928..

' Thet object'of this invention is to provide a isimfpleand reliablemechanism which is actuated for tensioning lthe main driving spring-by yperiodical electric impulses, the 2.0 intervals of which areA controlled by the runk ning of the time train.

This end is attained in the mechanism here? in chosen =ifor illustration by providing an electromagnet with two armatures, a main 2 driving armature and a supplemental circuit controlling armature carrie-d l*by the main armature, both of which are subject toi'the influence of the magnet; The main armature under the pull of the magnet tensions the time 39 train driving spring, lwhich spring as the time train runs causes the main armature to recede from the magnet until the supplemental' armature closes the electrical circuit and the main armature isagain drawn by the magnet andthe springv retensioned. The sup'- plemental armatureA carries a contact which closes the rcircuit through the magnet when the main'armature has receded to the desired degree, and is caused to open thecircuit when the main armature is attracted substantially its full distance, the supplemental armature being carried by the main armature and sub-k jected to the pull of the magnet withna lost motion connection.y springv is arranged to engage and delay or retard the movement of` the supplemental armature so that the lcircuit contacts are not instantlyy disengaged when the main armatureris attracted butA are held closed for a short intervalk by the pull .ofthe magneten the supplementalarmature'. The

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driving mechanism is connected with the time train. driving `arbor by positive means but which iscapableof slight expansion so as to lreeptheconnection close at theinstant that the main spring is tensioned,l and thus Acontribute in maintaining'the even driving pressure on thetimetrain.` n

kIn the accompanying drawings Fig. 1 is a view looking toward the back of a driving mechanism which embodies the invention, the

parts being in `the position occupied when the electric circuit is closed. Fig. 2 is a similar vienT with the circuit open. Fig. 3 is a view lookingat thek front of this mechanism. Fig. 4 is a View looking at 4one side of the driving mechanism. yltig. 5 isa view'looking at one end ot the driving mechanism. Fig. l6 shows an edge-view of the means whereby the drivingA mechanism is' connectedto the driving arbor. of the time'train. VFig. 7 is a pla-n view ot' a portion of theL connecting means.

lnfthe form of mechanism illustrated here'- in th-e magnet coils 1 are wound upon a core 2 which extendscompletely through the coils andthat at one end has an extensionrl, thus 'providingy poles atboth ends of the magnet. The magnet is fixed to the back of a plate Lland pivotally mounted on a post 5 that pro- 1' ects- `from the back of the plate is an L- shaped driving lever 6; This driving-lever is lmade of magnetic metal Aand comprises a main or primary-armature arm 7 extending across thecore at one end in position to be attractedfthereby, and an arm 8 that extends along theJ side of the magnet, the pivotal point y of the lever being at the apex of the angle. Onthe back side ofthe plate the swinging end of the arm 8 is bent outward and has a slot 9,' and extending from the arm 8 through an opening 10 in the. plate is a lug 1,1. Pivoted to this lug is a driving pawl 12 which is heldin engagementwith the ratchet wheel 18 onfthe Jfront of the plate by the main driving spring k14. i The driving spring is so arranged that it holds the .pawl in engagement with and tends to drive the ratchet wheel forwardfand also'tends to pull the arm 8 in rsuch rva direction `as to cause the arm 7 ofthe arma-ture to recede from the core of f they magnet as the spring through thepawl icc CII

ture shown is in the shapeof a spring drives the ratchet wheel forward. Then the arm 7 is drawn toward the core by the pull of held by a spring 150 in engagement with the Y ratchet wheel to prevent the backward movement of the ratchet Wheel when the vdriving pawl 12 is retracted. u i.

rl`he secondary or circuit controlling armager 16 which has one end fastened to the arm 8 of the driving lever. This spring fin# ger armature extends loosely through the` slot 9 in the bent end of the arm 8 so that while the secondary armature is carried by the driving-lever there is a little lost motion between these parts owing to the slot. The secondary Y armature 16 carries a contact 17 which is designed to engage afixedcontact 18 at the end of a yielding arm 19 that is fastened to the insulated piece 2O at the end of the magnet, and to which arm one end of the magnet winding is connected. The free end of the secondary armature is adapted to be attracted by the extension 3 of the magnet core. Fastened to the pole extension 3 is ra spring linger Q1 which has its free end bent outward and provided with a hump 22, which outwardly inclined end and hump extend into the path of the free end of the secondary armature.

When the contacts lof the secondary armature and arm 19 are engaged the magnet is energized so as to attract the main armature arm 7, retract the pawl over the ratchet wheel and tension the driving spring. During the first part of this movement of the main armature the magnetic pull of the core extension and the hump 22 of the spring finger hold the secondary armature with the circuit contacts enga-ged until the lost motion between the secondary and the main armature is taken up, and the pull of themagnet on the main 'armature is increased sufficiently to'cause the secondary armature to snap past the hump on the spring finger and thus open the circuitquiclrly. As the ratchet wheel rotates under the pull of the driving spring and the main armature recedes from the magnet the end of the secondary armature drags down the inclined end of the spring finger 21 until the contacts are nearly closed, and then when the end of the secondary armature reaches the hump in the spring linger it is under a slight tension, and owing to this tension it snaps past the hump and lightly engages the con- 17 with the fixed contact 18, which causes the core of the magnet to be slightly magnet'zed. rlhe slight magnetism thus ,developed in the core will act through the pole-piece 3y to attract the free end of the secondary armature 16 and hence pull the contacts 17 and 18 into tighter engagement with the eHect of correspondingly increasing the energy of the magnet until it is sufficient to pull the mainfinl armature arm 7 of the lever 6 inward against the counterurge of the driving-spring lei. This action of these parts is repeated each time the circuit is closed and opened through the secondary armature.

One end of the magnetwinding may be connected with the energizing circuit terminal at 23 and the otherend of the magnet vinding, as stated, is connected with the contact arm 19, while the other circuit terminal may be grounded on the plate at any suitable point as at 24.

The ratchet wheel, that is rotated by the pawl and driving spring, has two forwardly extending pins Qtliat are designed to, when the wheel is rotated by the push of the pawl, engage yielding lingers 26 that are attached to a disk 27 which is fastened to the arbor 28 of the time train, that may be any common and welllrnown type. Then `driving' pressure is exerted on the Vtime train these fingers close together and provide la positive driving'connection, but the fingers have sufficient resilience to bear against the pins, and keep in close engagement with the pins on the ratchet wheel at all times so as to ensure constantdriving pressure on the time train.

The invention claimed is: Y Y

1. In an operating-mechanism for electric clocks, the combination with an electro-magnet having two complementary pole-pieces; of a circuit therefor; a two-armed pivotal operating-lever having one arm carrying a main armature positioned for attraction by o-ne of thesaid pole-pieces and the other arm carrying a secondary armature mounted thereon with capacity for limited relative movement and positioned for attraction by the other of the said pole-pieces; a contactmember interposed` in the said circuit and 'operably connected to the said secondary armature; a second contact-member also inter-r posed in the said circuit and positioned to be engaged by the first-mentioned contact-member; anda drivingspring connected to the said lever and normally urging the primary armature away from its complementary polepiece and the said secondary armature toward its complementary pole-piece. Y

' 2. In an operating-mechanism for electric clocks, thecombination with an electro-magnet having two complementary pole-pieces; of Aa circuit therefor; an L-shaped pivotal operating-lever having two arms extending away from its pivot-point at substantial right angles; a main armature carried by one of the said arms and positioned for attraction by one of the said pole-pieces; a secondary armature mounted upon the other of the said arms with capacity for limited relative movement with respect .thereto and positioned for attraction by the other of the said pole-pieces; a contact-member interposed in the said circuit and operably connected to the said secondary armature; a second contactllt) member also interposed in the said circuit .and positioned to be engaged by the iirst-mentioned contact-member; and a driving-spring connected to the said lever and normally urging the primary armature away from its complementary pole-piece and the said secondary armature toward its complementary polepiece.

In an electriccloclr, the combination with an electro-magnet having two complementary pole-pieces; of a circuit therefor; a primary armature and a secondary armature connected together with capacity for limited relative movement and respectively positioned for attraction by one of the said complementary pole-pieces; a contact-member interposed in the said circuit and operably connected to the said secondary armature; a second contact-member also interposed in the said circuit and positioned to be engaged by the first-mentioned contact-member; and a driving-spring connected to the said primary armature and normally urging the same away from its complementary pole-piece and the said secondary armature toward its complementary pole-piece.

4. In an electric clock, the combination with an electro-magnet having an L-shaped core terminating in two complementary polepieces; a circuit therefor; a primary armature and a secondary armature connected together with capacity for limited relative movement and respectively positioned for attraction by one of the said complementary pole-pieces; a contact-member interposed in the said circuit and operably connected to the said secondary armature; a second contact-member also interposed in the said circuit and positioned to be engaged by the firstmentioned contact-member; and a drivingspring connected to the said primary armature and normally urging the same away from its complementary pole-piece and the said secondary armature toward its complementary pole-piece. n

5. Inv an electric clock, the combination With an electro-magnet having an L-shaped core terminating in two complementary pole-` pieces; a circuit therefor.;` a primary armature and a secondary armature arranged at a substantial right angle with respect to each other and connected together with capacity for limited relative movement and respectively positioned for attraction by one of the said complementary pole-pieces; a contactmember interposed in the said circuit and `operably connected to the said secondary armature; a second contact-member also interposed in the said circuit and positioned to be rengaged by the first-mentioned contact-member; and a driving-spring connected to the said primary-armature and normally urging the same away from its complementary polepiece and the said secondary armature toward its complementary pole-piece.

toward its complementary pole-piece; and

a driving-spring connected to the said primary armature and normally urging the same away from its complementary polepiece and the` said secondary armature toward its complementary 'pole-piece. y

7'. In an electric clock, the combination with an electro-magnet having two complementary pole-pieces; of a circuit therefor; a primary armature positioned for attraction by one of the said pole-pieces; a rresilient secondaryl armature connected .with the said primary armature `for actuation thereby with capacity for limited `relative movement with respect thereto and composed of a strip of other of the said pole-pieces; a contact-member interposed in the-said circuit and carried by the said resilient secondary armature; a second contact-member alsov interposed in said circuit and positioned to be engaged by the first-mentioned contact-member; and a driving-spring connected to the said primary armature and normally urging the same away from its complementary pole-piece and the said secondary armature toward its complementary pole-piece. Y

yspring' material extended into line with theA 8. In an electric clock, the combination Y with an electro-magnethaving an L-shaped core terminating in two complementary polepieces; of a circuit therefor; a primary armature positioned for' attraction by one ofthe said pole-pieces; a resilient secondary armature composed ofa strip of spring material and secured to the said primary armature and projecting therefrom at a substantial right `angle and positioned for attraction by the other of the said pole-pieces;'a contactmember interposed in the' said circuit and carried by the said secondaryarmature; a second contact-member also interposed in the said circuit and positioned to be engaged by the first-mentioned contact-member; and a driving-spring conneotedto the said primary armatureand normally urging the same away from its complementary pole-,piece and the said secondary armature toward its complementary pole-piece. k l

NEWTONy D. HOLBROOK. 

